German Patent Application No. DE 34 28 597 describes a fuel injection device in which a connecting element is designed as a U-shaped spring clamp to lock an injection valve to a pipe connector. The spring clamp has a web which extends transversely with respect to the longitudinal extent of the injection valve and legs which on the one hand engage, with tabs which are bent radially inwards at the edge, a circumferential groove on the valve housing of the injection valve, and on the other hand, have through-holes into which a locking collar on the pipe connector can be locked. In order to fix the spring clamp radially in the circumferential groove of the valve housing, the tabs have sections which extend concavely in a circular arc shape and whose radius corresponds to that of the circumferential groove.
During mounting, the spring clamp is first fitted onto the injection valve, the legs locking into the circumferential groove with their tabs. Then, the injection valve with the spring clamp is pushed into the pipe connector. The legs of the spring clamp are bent outwards so that they can slide away over the locking collar. As soon as the locking collar is locked into the through-holes, the legs spring back into their initial position. This ensures that the injection valves are secured axially on the pipe connector of the fuel distributor device, but does not provide protection against the injection valves rotating in the circumferential direction. Exact positioning of the injection valves is, however, desired if an exact injection geometry is to be maintained in multijet valves.
Furthermore, German Patent Application No. DE 39 19 231 describes a fuel injection device which ensures that the injection valve is connected to a pipe connector by snapping into place, mounting taking place comparatively simply. For this purpose, the pipe connectors are provided with radially outwardly pointing locking collars over which catch springs, which are attached to the injection valves in order to secure the injection valves, engage with lugs. Fixing webs are provided on the locking collar in order to permit the injection valves to be positioned exactly.
A connecting element for connecting an injection valve to a pipe connector which is coaxial thereto is also described in German Patent Application No. DE 39 04 479. The connecting element here is constructed as a plastic clip which is formed from a C-shaped disc with axially extending spring webs which in turn have locking noses. The disc engages a circumferential groove on the injection valve while the locking noses snap into place behind a locking collar on the pipe connector after the injection valve has been fitted coaxially into the pipe connector; complete protection against rotation again not being prevented.
U.S. Pat. No. 5,058,554 also describes elements for protecting against rotation, which elements are constructed in the form of closing springs, spring rings, snap rings or the like, and ensure that injection valves are secured to a fuel supply line. The securing elements are also formed as bent wire clasps which contribute to securing in a resilient way.
Furthermore, connecting elements with anti-rotation protection are also described in other fields in which components have to be connected to one another exactly. In injection valves, connecting elements which have anti-rotation protection, such as is shown in European Application No. 0 565 867, are also used in connections which serve to produce electrical contacts.